package com.zans.utils;


import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.util.Base64;


/**
 * The type Aes util.
 *
 * @author pancm
 * @Title: AESUtil
 * @Description: AES  加密工具类
 * @Version:1.0.0
 * @date 2018年4月3日
 */
public class AESUtil {


    //使用AES-128-CBC加密模式，key需要为16位,key和iv可以相同！
    private static String KEY = "Lgwy@1234!@#$%^&";

    private static String IV = "Lgwy@1234!@#$%^&";


    /**
     * 加密方法
     *
     * @param data 要加密的数据
     * @param key  加密key
     * @param iv   加密iv
     * @return 加密的结果
     * @throws Exception
     */
    public static String encrypt(String data, String key, String iv) throws Exception {
        try {

            Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");//"算法/模式/补码方式"NoPadding PkcsPadding
            int blockSize = cipher.getBlockSize();

            byte[] dataBytes = data.getBytes();
            int plaintextLength = dataBytes.length;
            if (plaintextLength % blockSize != 0) {
                plaintextLength = plaintextLength + (blockSize - (plaintextLength % blockSize));
            }

            byte[] plaintext = new byte[plaintextLength];
            System.arraycopy(dataBytes, 0, plaintext, 0, dataBytes.length);

            SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), "AES");
            IvParameterSpec ivspec = new IvParameterSpec(iv.getBytes());

            cipher.init(Cipher.ENCRYPT_MODE, keyspec, ivspec);
            byte[] encrypted = cipher.doFinal(plaintext);
            return Base64.getEncoder().encodeToString(encrypted);

        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * 解密方法
     *
     * @param data 要解密的数据
     * @param key  解密key
     * @param iv   解密iv
     * @return 解密的结果
     * @throws Exception
     */
    public static String desEncrypt(String data, String key, String iv) throws Exception {
        try {
            byte[] encrypted1 = Base64.getDecoder().decode(data);

            Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
            SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), "AES");
            IvParameterSpec ivspec = new IvParameterSpec(iv.getBytes());

            cipher.init(Cipher.DECRYPT_MODE, keyspec, ivspec);

            byte[] original = cipher.doFinal(encrypted1);
            String originalString = new String(original);
            return originalString;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * 使用默认的key和iv加密
     *
     * @param data
     * @return
     * @throws Exception
     */
    public static String encrypt(String data) throws Exception {
        return encrypt(data, KEY, IV);
    }

    /**
     * 使用默认的key和iv解密
     *
     * @param data
     * @return
     * @throws Exception
     */
    public static String desEncrypt(String data) throws Exception {
        return desEncrypt(data, KEY, IV);
    }


    /**
     * 加密
     * @param sSrc
     * @return
     * @throws Exception
     */
    public static String encryptPadding(String sSrc) throws Exception {
        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        byte[] raw = KEY.getBytes();
        SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
        //使用CBC模式，需要一个向量iv，可增加加密算法的强度
        IvParameterSpec iv = new IvParameterSpec(IV.getBytes());
        cipher.init(Cipher.ENCRYPT_MODE, skeySpec, iv);
        byte[] encrypted = cipher.doFinal(sSrc.getBytes("utf-8"));
        //此处使用BASE64做转码。
//        return new BASE64Encoder().encode(encrypted);
        return  Base64.getEncoder().encodeToString(encrypted);

    }


    /**
     * 解密
     * @param sSrc
     * @return
     */
    public static String decryptPadding(String sSrc) {
        try {
            byte[] raw = KEY.getBytes("ASCII");
            SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            IvParameterSpec iv = new IvParameterSpec(IV.getBytes());
            cipher.init(Cipher.DECRYPT_MODE, skeySpec, iv);
//            byte[] encrypted1 = new BASE64Decoder().decodeBuffer(sSrc);//先用base64解密
            byte[] encrypted1 = Base64.getDecoder().decode(sSrc);//先用base64解密
            byte[] original = cipher.doFinal(encrypted1);
            String originalString = new String(original, "utf-8");
            return originalString;
        } catch (Exception ex) {
            return null;
        }
    }



    public static void main(String[] args) throws Exception {
//        String test1 = "sa";
//        String test =new String(test1.getBytes(),"UTF-8");
//        String data = null;
//        String key =  KEY;
//        String iv = IV;
//        // /g2wzfqvMOeazgtsUVbq1kmJawROa6mcRAzwG1/GeJ4=
//        data = encrypt(test, key, iv);
//        System.out.println("数据："+test);
//        System.out.println("加密："+data);
//        String jiemi =desEncrypt("/+eo4MFEr6ePFKRbAt97Lg==", key, iv).trim();
//        System.out.println("解密："+jiemi);


    }

}
